Simultaneous coordination and double activation phenomena of carbonyl and epoxy oxygen by bis-titanium reagent as a bidentate lewis acid catalyst

Article abstract of DOI:10.1016/S0040-4039(98)00571-1

The new bidentate Ti catalyst, (anthraquinone-1,8- dioxy)bis(triisopropoxy-titanium) (1) can be successfully designed and utilized for the simultaneous coordination to carbonyl substrates. The high double-activation ability of the bidentate Ti catalyst 1 toward carbonyls is emphasized using several synthetic examples in comparison with the corresponding monodentate Ti catalyst. The intermediary coordination complex formation of bidentate 1 with DMF or epoxycyclohexane as a carbonyl or epoxy substrate is characterized by ¹³C NMR spectroscopy.